Examples of a process for producing a hydrophilicity-carrying polymeric material are:
(1) a process comprising the step of sulfonating a synthetic pulp containing polyethylene as a major component in a concentrated sulfuric acid or a fuming sulfuric acid, thereby producing a hydrophilicity-carrying textile material (JP 8-260346A); and
(2) a process comprising the step of radiation-initiated graft polymerizing hydrophilic monomers and monomers having ion-exchange groups in the presence of polymeric substances, thereby producing polymeric substances having hydrophilicity and ion-exchange groups (U.S. Pat. No. 5,648,400A).